Honestly I believe this to be a way more important issue to discuss than the whole capitalism vs socialism vs communism vs whatever else argument. If your ideas can easily be perverted by corruption then it won't work.

I have some ideas but I'm just some idiot on the internet. I think you need checks and balances. Have at least two groups with similar power at odds with one another. One example is corporation vs government. But I don't think just 2 groups is good enough. Ideally you probably want 3 groups at the very least. I know many governments around the world already uses this sort of structure internally (eg different branches of government), but I don't think these solutions take into account the existence of mega corporations that can act across country borders.